In the field of noise barriers, façade components, and paneling with transparent or translucent segments, a topic that continues to increase in importance is bird impact. A wide variety of structures and markings have been proposed in the past for preventing birds from flying into transparent areas.
The use of markings featuring UV absorption is known from a variety of sectors, e.g. that of ID cards, described by way of example in EP 2 179 857 A1.
EP 1 319 335 A1 by way of example describes the marking of transparent materials via mechanical, physical, and/or chemical treatment. It is proposed that the better capability of birds to perceive UV light is utilized to provide bird-protection devices.
DE 10 2011 103 132 A1 describes a glazing unit with a structure for protection from bird impact, where the arrangement has said structure on at least one side of the glazing unit, and said structure is perceived by the eye of a bird to be an obstruction through which it is not possible to fly, where luminescent pigments which absorb in the UV region and, by means of Stokes shift, emit in the longer- or shorter-wavelength region have been admixed with the graphic coating elements.
On the other hand, H. Haupt, Berichte zum Vogelschutz [Bird protection reports], volume 47/48, 2011, 143-160 indicates that it would be premature to describe UV markings as sufficiently effective for the prevention of bird impact.
More recent studies also confirm that the conventional application of traditional raptor silhouettes is not adequately effective.
It has been found that markings in the form of stripes or spots on a transparent element are more effective than the known raptor silhouettes in preventing bird impact, where these markings are applied in the form of adhesive strips after manufacture of the transparent segment. An alternative to this is the possibility of using screen printing or other layer-forming application processes to place markings on the surface of the transparent segments.
The disadvantage of both processes for the application of markings is that they involve a great deal of work and therefore incur considerable additional costs. Modifications of this type applied to the surface moreover exhibit weathering phenomena and peeling after a number of years in outdoor use, and thus become ineffective.
Processes for using lasers for the marking of transparent construction elements are in principle known, being described by way of example in DE 34 02 871 A1 and also in J. Bosman, Processes and strategies for solid state Q-switch laser marking of polymers, doctoral thesis, Enschede, 2007, ISBN 978-9-03-652346-2.